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based on model assumptions,to help document outreach success, and to serve as potential <br /> examples for pilot outreach locations (see Appendix A). <br /> 2.1 MEP MODEL-LOADING ASSUMPTIONS <br /> The Pleasant Bay MEP model accounts for nitrogen from both controllable sources (i.e.,human <br /> input) including fertilizers, impervious surfaces, and wastewater(both from septic systems and <br /> wastewater treatment facilities), and from sources outside the watershed such as atmospheric <br /> deposition on natural areas and water bodies. The MEP model also accounts for nutrient loading <br /> attenuation from water bodies. This analysis of the MEP model focuses on fertilizer inputs to the <br /> Pleasant Bay sub-watersheds and does not account for attenuation,which potentially occurs for <br /> certain sub-watersheds. Assumptions and sources for nitrogen inputs to the Pleasant Bay <br /> watershed model are listed below. <br /> It should be noted that the MEP model assumes a 20% leaching rate for fertilizer applications to <br /> turf(e.g., lawns and golf courses). A 2008 literature review by Dr.Petrovic, commissioned by <br /> the Pleasant Bay Alliance, indicated that a fertilizer leaching rate of 10%for lawns and golf <br /> courses is appropriate. A 2009 Massachusetts Department of Environmental Protection(DEP) <br /> study, conducted by HW, confirmed that based on Cape Cod soils and other factors, existing <br /> literature supports a 20%leaching rate for lawns and golf courses. TMDL estimates are based <br /> on the MEP model and its assumptions, and any credit from fertilizer reduction to the Pleasant <br /> Bay watershed would likely use similar assumptions. Fertilizer leaching rates were therefore not <br /> analyzed as part of this project, and the 20% leaching rate assumption is provided here for <br /> reference. <br /> Residential properties <br /> • Fertilized lawn area for transient and non-transient residences (Source: CCC Technical <br /> Bulletin 91-001, "Nitrogen Loading"): 5,000 square feet(sq. ft.) <br /> • Nitrogen application to residential lawns (Source: Howes Lawn Survey in Poppy,Three Bay <br /> Watersheds): 1.08 pounds (lbs)/1,000 sq. ft. <br /> • Leaching rate for residential applications (Source: Howes Lawn Survey in Poppy,Three Bay <br /> Watersheds): 20% <br /> Cranberry bogs <br /> • Area actively used: 85% of parcel <br /> • Nitrogen application(Source: Howes and Teal, 1995): 31 lbs/acre(0.72 lbs/1,000 sq. ft.) <br /> • Leaching rate(Source: Howes and Teal, 1995): 66% (i.e., 34%attenuation) <br /> Municipal Properties <br /> • Nitrogen application to public parks/school properties(Source: CCC Technical Bulletin 91- <br /> 001, "Nitrogen Loading"): 3 lbs/1,000 sq. ft. <br /> • 'Leaching rate for municipal applications (Source: Howes): 20% <br /> It should be noted that no fertilizer loads were estimated for municipal properties in the <br /> watershed,but the assumptions above were listed in the model. Based on an analysis of aerial <br /> photography and MassGIS land use within the Pleasant Bay watershed,HW determined that the <br /> Pleasant Bay Fertilizer Management Plan 2 Horsley Witten Group,Inc. <br /> Final Report December 2010 <br />